drooping is typically caused by too much moisture (at the roots) or too much heat combined with humidity. Again like I mentioned, since your plants look healthy otherwise it is likely overwatering. Saying you have holes in the bottom of the pot is fine assuming the water isn't just pooling underneath the pot and not actually leaving the pot.
Proper drainage is just as important as watering ...soil in pots don't dry out very fast in cooler temperatures like 70 degrees.
Example: I kept my leftover soil in a 5 gallon plastic pail with a lid for almost 9 months, spring to autumn. Because it was in a cool dark place in my garage, it was still very moist when I opened it up again. I was quite surprised how much moisture it had retained throughout the soil, for being in a dry place so long. At some points in the summer it got up to 85 degrees in there for many days and it still didn't dry out. The lid obviously helped but then the lid is like proper drainage...with no place for moisture to go, it takes a longer period of time for it to evaporate...in the case of drainage it affects the rots because they essentially they suffocate